von rauschenplat



G. VON RAUSCHENPLAT.

PROCESS FOR REMOVING-IRON FROM TIN ORES. APPLICATION FILED JAN. 28, 1914.

1,1 96,0419. I Par1'1tedAug..29, 1916.

2 SHEETS-SHEET I.

e. vow RAUSCHENPLAT.

PROCESS FOR REMOVING IRON FROM TIN ORES,

APPUCATION FILED )AN.28, 1914.

1.196349, Patented Aug. 29, 1916 2 SHEETS-SHEET 2.

@ATENT OFFICE.

GllNZEL VON RAUSCHENPLAT, OF STEGLITZ, GERMANY, .ASSIGNOR TO BARILLA LIM- ITED. OF LONDON, ENGLAN D, A CORPORATION OF GREAT BRITAIN.

PROCESS FDR EEIVIQVING IRON FROM TIN ORES.

i ,"lSNiJl-ii).

Application filed January 28, 1914.

Be it known that l, lli'nzyuu, VON liar;- SCIH'INILA'P. a subject of the. German Emperor. and resident of hitcglitz. Germany, have invented certain new and useful In]- prorenu-uis in Processes for Removing Iron from 'liu Ores. of which the following is a specification.

Iron is one of lhc most lluwehohie admixtures in tin ores. since it is reduced to the metallic statc in the smelting of'the ores in the calcium or furnace. or is issolniid' in the tin bath and causes losses of tin owing to the formation of hard heads"; generally s1) akinc. as much tin is lost as there is iron contained in the ore. in order to reduce. this drawback. it has been proposed to remove the iron from the o: in different ways, as by mechanical dressing. anagram-tic separation. and especially treating the concentrates with chemical solvents. for exauuplc hydrochloric acid. The ores corain the iron in the form 01 oxids or sulfids which by the converted into oxids roastingoperation a ju the other soluble orf with diilicnlty'. hand, .llXlfiil'liOll will prodm compounds which are :dmaclu l only -tly even by concentrated acids. and therefore the final product obtained still contains a certain proportion of iron.

I hare dismfavered that it is possible to obtain a bcttcr extraction of iron in the lixiviacing of tin ores by using atrcatuiont according to which the higher iron oxids of the original or if necessary roasted) orein some cases after a preliminary concentration by any approved or Well-lmoavn dressing process-m re converted nto products readily soluble in acids. for instance into l ed) FeO. or Fe. For the reduction of these higher oxids, I may eurploy any of the curetomary reducing agents, for instaiu-c soud coal, carbon mouoXid, or h urogen. taking care to keep the temperature so low that tho cassiterite is not attached all or but incompletely, so that there will be present a tin-oxygen compormd insoluble in a ids I prefer to use gaseous wcdm agents since with them it easier to war, the reduction and to prevent coutaiuimdion by ashes. For hastening the reduction I employ tcnuicra tures lying" between 300 and 500 wutigrado, according to the nature of the orc. With these temperatures, tho major part of the iron -is obtained in the formv of Fat), and

Specification of Letters Patent.

Patenteri Aug. 29, 1916.

Serial No. 815,029.

ciple, if necessary with heating of the lyes or preferably hydrochloric ac1d gas. The.

dry reaction product is treated with this acid at temperatures lying between 400 and 500 ceutigradc. The iron is distilled in the form of Volatile chlorid.

The accompanying drawing shows, in diagrammatic sections. three different forms of apparatus suitable for carrying out my improved process, Figures 1 and 3 being vertical sections. and Fig. 2 a horizontal section.

As an example of the procedures which may he adopted according to my invention, 1 will describe the following with reference toFig. 'l The ore, after being crushed to a. fineness of from 9 to 5 millimeters is fed at a into a revolving furnace A, which also receivcs a supply of reducing gases, such as producer-gas from a producer B, hydrogen, coke-oven gas, or blast-furnace gases, ad mitted, say through a pipe A; at the lower end of the revolving furnace or drum. This drum and the material therein are heated either externally, or as shown by preheating the reducing gases on their Way to said drum. for instance in iron superheater tubes A. The gases which have been used for the reduction may. after leaving the drum a a, be used for heating tho apparatus (J in which the gas is preheated, as by diyerting a. portion of such Waste gases to said apparatus through a branch pipe at".

According to another species of my invention, the ore, with the addition of a medium soluble in water or in acids (lime or pitch being examples of such mediinns) is pressed into bricks, sawdust be ng added in some cases for producing porosity and aparlial reduction. These bricks are then stacked in a suitable furnace (see the chambers D in Fig. 2), say, a hiiendheimfurnace, and ar heated to the proper reduction temperature by means of a reducing flame of a gas supplied through pipes y D from. the producer E and one of the regenerators F. Subsequently, the material is cooled by a separate stream of reducing gases supplied through pipes G and cooled in cooler H.

In this case also I prefer to resort to indirect heating, by preheating the reducing gases in iron or brick apparatus or regenera tors F of the type known as blast-heaters, the spent reducing gases being used as fuel or heating medium in such apparatus.

A third way of carrying out my improved process consists in delivering the ore to a furnace J, (see Fig. 3), similar to a puddling furnace, with superposed. circular plate-like hearths K, K, furnaces of this type being used, for instance, as'drying fun naces for the raw material in the manufac ture of lignite briquets. In this furnace, the ore is moved or fed by means of rake arms L, so as to pass successively. over the several hearths, from the top to the bottom of the, furnace. The upper hearths K are heated to the reaction temperature in any suitable manner, for instance by means of fresh gas heated in a separate apparatus (not shown) and then passed through a pipe M and through the hollow upper hearths K to be admitted subsequently to the furnace at the bottom through a pipe N. Cooling Water is circulated through the lower hearths K, by means of a pipe 0 for the purpose of quickly bringing the ore to a temperature below the one at which re-oxidation will take place in the presence of air.

The completion of the reductioriis ascertained either by a lixivi ation test made with a small quantity of treated ore, or simply by observing a characteristic darkening of the color of the ore. The reduction having been completed, the iron contained. in the ore is removed either by washingthe prod-- not with aqueous hydrochloric or sulfuric acid in wood or iron vats or in' revolving drums leaded or lined, whereupon the'ore is separated from the lye, say in settling tanks; or, the iron may be removed by means of hydrochloric acid gas in horizontal retorts prov .4 6 with screw agitators and heated. externally. It will be understood tin he nature of the ore to be treated W11].

determine the character of theapparatus to be employed.

1 claim as my invention:

1. The herein described process for removiron from iron-bearing tin ores, which consists in subjecting the ore to a reducing treatment at a temperature at which the tin will remain. in a form insoluble in acids, while the iron. contents will be reduced to a form. readily soluble in acids, and then subjecting the resulting product to treatment with acid. Y

2. The herein described process for removing iron from ferruginous tin ores,

which consists in. subjecting the materiah'in.

a condition in which the tin is present as oxid, to a reducing treatment at a temperature at whioh'the tin will remain in a form insoluble in acids, and then subjecting the resulting product to treatment with acid.

3. The herein described process for removing iron from ferruginous tin ores,

which consists in subjecting the material, in

a condition in which the tln is present in oxidized term, to a reducing treatment at a temperature not exceeding 500 centigrade, 

